(1) Field of the Invention
The present invention relates to an image forming device, and more specifically, to an image forming device that reads out an image from a document managed by management level information and forms the read-out image onto a recording sheet, and relates to a recording sheet selection method for the image forming device.
(2) Description of the Related Art
Use of contactless IC tag as a means for managing the document security has been studied by business organizations and the like. More specifically, according to a technology, the document security is managed by using a contactless IC tag embedded in the document, where the contactless IC tag stores management level information which has conventionally been represented by a sign “FOR INTERNAL USE ONLY” or “CONFIDENTIAL” stamped on the document.
This technology produces such an advantageous effect that documents are clean and easy to see since information (such as “FOR INTERNAL USE ONLY”) that is irrelevant to the contents of the documents is eliminated. Also, by installing an IC tag reader in an entrance of a building or a room in which security-target documents are stored, it is possible to check documents when they pass the entrance, to prevent the documents from being taken out in an unauthorized manner.
Meanwhile, when a document embedded with a contactless IC tag is copied by an image forming device, it is necessary to pass (succeed) the management level information from the document to a recording sheet. For this reason, when a document embedded with a contactless IC tag is copied by an image forming device, the management level information needs to be read out from the contactless IC tag embedded in the document and written into a contactless IC tag embedded in a recording sheet.
Also, when a document is newly managed for security using the contactless IC tag, it may be necessary to copy an image from the document to a recording sheet embedded with a contactless IC tag, and write the management level information to the contactless IC tag embedded in the recording sheet.
In principle, an image forming device stores ordinary recording sheets that do not have such tags, as well as recording sheets embedded with the contactless IC tag. It is therefore necessary to select, in an assured manner, a recording sheet embedded with a contactless IC tag to perform the above-described process. On the other hand, when an ordinary document (a document at a low management level) is copied, it is necessary to select an ordinary recording sheet. That is to say, it is necessary to select a recording sheet depending on the management level of the document.
Japanese Patent Application Publication No. 2005-208098 discloses an image forming device that includes (a) an operation panel on which it is possible to set the device to be restricted to use only a recording sheet embedded with a contactless IC tag when a copy is performed, and to cancel the setting, and (b) an IC tag reader that is disposed at a midway position in the transport path from the sheet tray and the image forming means. In this image forming device, the image forming means is stopped from forming (copying) an image when the above-mentioned restriction on the recording sheet for use has been set on the operation panel, and when the IC tag reader does not read out any information from a recording sheet fed out from the sheet tray (that is to say, when recording sheets attached with no contactless IC tag are stored in the sheet tray).
Such a construction prevents, with a considerable degree of reliability, a case where a document with high management level, which should be copied onto a recording sheet attached with a contactless IC tag, is copied onto a recording sheet attached with no contactless IC tag by mistake.
However, in the image forming device recited in Japanese Patent Application Publication No. 2005-208098, it may happen that if the above-mentioned setting has been cancelled on the operation panel, a document with low management level, which should be copied onto a recording sheet attached with no contactless IC tag, is copied onto a recording sheet attached with a contactless IC tag. Since a recording sheet attached with a contactless IC tag is more expensive than a recording sheet attached with no contactless IC tag, such copying leads to unnecessary increase in the office expense. Also, in the image forming device recited in Japanese Patent Application Publication No. 2005-208098, even a document with high management level is unconditionally copied if the setting has been cancelled. This is a problem for security.